I got the 40 series delta flow... with a high flow cat... and dual 3" tips. I think its good. I didnt want it too loud. My friend got single in single out on his Jeep v6 and its loud... so id think on a 350 or wahtever, itd bepretty loud. To me loud gets anoying after a while, thats why i opted for Delta series not loud but its alot deeper than stock... its all your preference, if you like ear drum bustin grumble or just like the mellow humm...
87 Custom Deluxe
305/Sm465/ NP208
4.56 , 35" BFG Muds, CatCo Cat & Series 40 delta flow 3" tips.
6"Springs, Tranny, & Engine coming soon.